Innovative, Gemini-Type Molecular Defoamer Technology for Improved Coating Aesthetics.

The use of conventional surfactants and defoamers in waterborne coatings can often create an undesirable cycle, whereby each imparts a negative effect that requires the other to solve. Molecular defoamers represent a novel class of defoamers that break foam on a molecular level, which is unlike conventional defoamers that utilize macroscopic physical incompatibility within a coating formulation. This is accomplished by the ability of the molecular defoamer to adsorb at the air-water interface of a foam bubble and, thereby, displace some of the surfactants that stabilize the foam. Based on a fundamental understanding of the effects of basic adsorption parameters, innovative nonsilicone molecular defoamers were developed that provide long-term foam control, effectively reduce both surface tension and foam in a variety of emulsion polymers, and decrease significantly the level of defects in waterborne coating applications. A synergistic performance benefit was obtained when these molecular defoamers were used in combination in an acrylic, industrial maintenance formulation. [ABSTRACT FROM AUTHOR]